ABSTRACT
ABSTRACT Objective: To evaluate the usefulness of a device for collecting and preserving human papilloma virus (HPV) DNA in self-collected vaginal samples stored dry during 14 days. Materials and methods: Diagnostic concordance pilot study that included non-pregnant women over 25 years of age with a biopsy-confirmed result of cervical intraepithelial neoplasia (CIN) grade 1 or more, coming to two referral centres in Bogotá, Colombia. Women with a history of total hysterectomy were excluded. Convenience sampling was used. The device uses real-time PCR (polymerase chain reaction) for DNA detection. Sociodemographic and clinical variables were measured, as well as the results of the test when the sample was collected by the patient and when it was collected by the physician, and the amount of DNA in the samples taken and processed on day 1, and in those processed on day 14, using Ct thresholds. Descriptive statistics were applied. Overall concordance was estimated by means of the kappa coefficient and mean differences in DNA amount. Materials and methods: Diagnostic concordance pilot study that included non-pregnant women over 25 years of age with a biopsy-confirmed result of cervical intraepithelial neoplasia (CIN) grade 1 or more, coming to two referral centres in Bogotá, Colombia. Women with a history of total hysterectomy were excluded. Convenience sampling was used. The device uses real-time PCR (polymerase chain reaction) for DNA detection. Sociodemographic and clinical variables were measured, as well as the results of the test when the sample was collected by the patient and when it was collected by the physician, and the amount of DNA in the samples taken and processed on day 1, and in those processed on day 14, using Ct thresholds. Descriptive statistics were applied. Overall concordance was estimated by means of the kappa coefficient and mean differences in DNA amount. Results: A kappa coefficient of 0.84 (95% CI: 0.71-0.96) was found for concordance in high-risk HPV detection between the self-collected cervicovaginal sample and the sample taken by the clinician. There were no differences in terms of the amount of viral DNA between day 1 and day 14 (DM -0.34 cycles; 95% CI: - 2.29 to 1.61). Conclusion: Self-collected vaginal samples using the storage device are reliable for high-risk HPV detection in patients with cervical dysplasia, and preserve viral DNA for 14 days if stored dry at room temperature. Confirmation studies in the general population are required.
RESUMEN Objetivo: Evaluar la utilidad de un dispositivo para toma y preservación del DNA del virus del papiloma humano (VPH) de muestras vaginales recolectadas por autotoma y almacenadas en seco durante 14 días. Materiales y métodos: Estudio piloto de concordancia diagnóstica. Se incluyeron mujeres mayores de 24 años no gestantes con un resultado de neoplasia intraepitelial cervical (NIC) grado 1 o más, confirmado por biopsia en dos instituciones de referencia en Bogotá, Colombia. Se excluyeron mujeres con antecedente de histerectomía total. Se realizó un muestreo por conveniencia. El dispositivo utiliza PCR (reacción en cadena de la polimerasa) en tiempo real para detección del ADN. Se midieron variables sociodemográficas y clínicas, así como el resultado de la prueba por autotoma y tomada por el médico, y la cantidad de ADN de las muestras tomadas el día 1 procesadas ese día, y el día 14, por medio del Ct umbral. Se realizó estadística descriptiva. Se calculó la concordancia global por medio del índice de kappa ponderado y la diferencia de medias de la cantidad de ADN. Resultados: La concordancia en la detección de VPH de alto riesgo mostró un kappa = 0,84 (IC 95 %: 0,71-0,96) entre la muestra cervicovaginal recolectada por autotoma frente a la muestra cervical recolectada por el médico. No hubo diferencias en la cantidad de ADN viral entre el día 1 y el 14 (DM -0,34 ciclos; IC 95 %: -2,29 a 1,61). Conclusión: Las muestras vaginales recolectadas por autotoma usando el dispositivo de almacenamiento son confiables para la detección de VPH de alto riesgo en pacientes con displasia cervical, y preservan el ADN viral por 14 días si se almacenan en seco a temperatura ambiente. Se requieren estudios en población general para poder confirmar.